The Chargers’ defense played a part in this, too. A collapse of the highest order was equal parts excellent quarterbacking and a conservative defensive approach that produced a 35-24 victory for the Broncos on Monday night at Qualcomm Stadium.

The Chargers’ defense dictated tempo in a masterful first-half performance. In the second half, this tortoise went back into its shell. The Chargers played it safe in an attempt to prevent big plays that would facilitate a seemingly insurmountable comeback.

“I think our intention was to stay aggressive and continue to go after them,” Chargers coach Norv Turner said. “I thought they protected a little better in the second half and gave Peyton time to throw. I thought (defensive coordinator John Pagano) mixed things well throughout the game.”

It didn’t work well enough. The Chargers rolled over, played dead and let Manning execute at will.

Manning threw five incompletions in the first half. In the second, he threw one. He was 13-for-14 for 167 yards and three touchdown in the second half in a dominant performance. His first incompletion came late in the fourth quarter with the game virtually in hand.

“Win or lose, you’re supposed to move after 24 hours and focus on the next one,” Chargers free safety Eric Weddle said. “That’ll be hard. This is a loss that can stick with you all season.”

The Chargers saw this Mack truck coming down the pike, and they still couldn’t get out of the way.

“We came out the second half knowing they were going to throw,” strong safety Atari Bigby said. “We knew they were going to almost exclusively with a no-huddle. We knew that and we couldn’t stop it well enough.

“We have to get to the point where we’re executing with consistency. We’re giving great effort and not always getting great results. The stats from the first half to the second are like night and day. There’s no excuse for that. The same team we controlled in the first half got loose in the second half, and we let that happen. We simply can’t have that.”

The Broncos could do no right in the first half. They rolled through the second. The Broncos marched 85 yards on eight plays, and five of them were completions of more than 10 yards.

The Chargers could do nothing to stop the attack. They didn’t respond fast enough when Manning got the ball out quick. They didn’t generate enough pressure when Manning sat back and waited for a big play to develop.

“There were a couple times he made good play,” Weddle said, “and there were a couple times we let him off the hook.”

The Broncos were moving fast with a no-huddle offense, pushing his offense and the defense to the brink.

“We were ready for the fast pace,” defensive end Corey Liuget said. “They didn’t do anything that we weren’t prepared for. We just couldn’t make key stops at key times.”

The Chargers said they remained upbeat during a physically and mentally exhausting half, always hoping that one big play could cauterize the wound and stop the bleeding.

That never happened. The aggressiveness the Chargers played with in the first half largely disappeared.

“It only takes one play to turn things around, and we held that belief throughout the second half,” Weddle said. “We lost momentum and couldn’t get it back. We didn’t respond well to the adjustments we knew were coming. Peyton made some unbelievable throws, which we knew he would, but we didn’t counter with big plays of our own. In the end, it cost us.”